/*
 * Copyright 2009-2009 Tanesha Project. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, 
 *    	 this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright notice,
 *    	 this list of conditions and the following disclaimer in the documentation 
 *    	 and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT ``AS IS'' AND ANY EXPRESS OR 
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
 * SHALL THE FREEBSD PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 *  OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those 
 * of the authors and should not be interpreted as representing official policies, 
 * either expressed or implied, of the Tanesha Project.
 */
package com.google.api.chart;

import java.awt.Dimension;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.google.api.chart.encoding.DataEncoder;
import com.google.api.chart.encoding.JoinHelper;

public class URLHelper {

	public static String CHART_URL = "http://chart.apis.google.com/chart?";

	/**
	 * Forms an HTTP request and parses the response for a detection.
	 */
	protected static byte[] retrieveURL(final String url) throws Exception {
		try {
			final HttpURLConnection uc = (HttpURLConnection) new URL(url).openConnection();
			try {
				
				byte[] buf = new byte[1024];
				
				ByteArrayOutputStream bout = new ByteArrayOutputStream();
				InputStream in = uc.getInputStream();
				while (true) {
					int rc = in.read(buf);
					if (rc <= 0)
						break;
					bout.write(buf, 0, rc);
				}
				
				return bout.toByteArray();
			} finally { // http://java.sun.com/j2se/1.5.0/docs/guide/net/http-keepalive.html
				uc.getInputStream().close();
				if (uc.getErrorStream() != null) {
					uc.getErrorStream().close();
				}
			}
		} catch (Exception ex) {
			throw new Exception("Error retrieving data: " + ex.getMessage(), ex);
		}
	}

	public static String buildURL(ChartTypeMaker type, Dimension size, DataEncoder dataEncoder, List<DataSeriesMaker> dataSeries) {
		StringBuilder buf = new StringBuilder(CHART_URL);
		
		List<String> parameters = new ArrayList<String>();
		List<String> chmParameters = new ArrayList<String>();

		// type
		parameters.add("cht="+type.toString());
		// size
		parameters.add("chs="+size.width+"x"+size.height);
		// data
		parameters.add("chd=" + dataEncoder.encode(dataSeries));

		// add layout parameters from the type.
		type.fillParameters(parameters, chmParameters);
		
		for (Iterator<String> it = parameters.iterator(); it.hasNext(); ) {
			buf.append(it.next());
			if (it.hasNext())
				buf.append("&");
		}

		if (chmParameters.size() > 0)
			buf.append("&chm=" + JoinHelper.join(JoinHelper.array(chmParameters, String.class), "|"));
		
		return buf.toString();
	}
}
